Example: 4/9 and 9/4 are reciprocals because 4/9 x 9/4 = 1
The numerator (top number) and denominator (bottom number) are switched when you find the reciprocal.
Use it when you are trying to divide by a fraction. Remember this by thinking "Invert and multiply" Like: 3/5 รท 1/3 could be solved by doing 3/5 times the reciprocal of 1/3 which is 3/1. Note: "Invert and multiply" is only used for dividing fractions/mixed numbers, not multiplying.
Key Concepts:
To divide a fraction by a fraction (Lesson 5-3)
You don't have to have common denominators like when you add and subtract fractions.
"Invert and multiply"
Multiply the first number (leave it alone!) by the reciprocal of the second number.
Example: 9/16 3/4 could be solved by doing 9/16 x 4/3. Cross cancel the 9 and the 3 and the 16 and the 4.
You'll get 3x1=3 for the numerator and 4x1=4 for the denominator so that would be the fraction 3/4 in simplest form.
To divide a whole number by a fraction you write the whole number into a fraction and that would be blank over 1
Solving Algebraic Fractions Equations by Multiplying (Lesson 5-5)
First you take the second fraction and you flip it upsidown to get a reciprocal. Then since you multiplied on that side you have to multiply the number that it equals by that and you get your answer.
Divide to find the number of cupcakes in a row to cover the length of the box.
17 1/2 divided by 1 1/4 = 35/2 divided by 5/4 = 35/2 times 4/5 then cross cross cancel which would be 7 times 2 = 14/1 and 14 times 1 = 14 so 14 cupcakes would be your answer to step 1.
Divide to find the number of cupcakes to cover the width of the box.
13 3/4 divided by 1 1/4 = 55/4 divide by 5/4 = 55/4 times 4/5 then cross cancel which would be 11/1 times 1/1 = 11 because 11 times 1 = 11 so your answer to step to would be 11 cupcakes.
All togheter would be 11 times 14= 154 cupcakes.
Math Chpt. 5 Study Guide
Terms to Know:
Reciprocal (Lesson 5-3)
Key Concepts:
To divide a fraction by a fraction (Lesson 5-3)
Solving Algebraic Fractions Equations by Multiplying (Lesson 5-5)
First you take the second fraction and you flip it upsidown to get a reciprocal. Then since you multiplied on that side you have to multiply the number that it equals by that and you get your answer.
Divide to find the number of cupcakes in a row to cover the length of the box.
17 1/2 divided by 1 1/4 = 35/2 divided by 5/4 = 35/2 times 4/5 then cross cross cancel which would be 7 times 2 = 14/1 and 14 times 1 = 14 so 14 cupcakes would be your answer to step 1.
Divide to find the number of cupcakes to cover the width of the box.
13 3/4 divided by 1 1/4 = 55/4 divide by 5/4 = 55/4 times 4/5 then cross cancel which would be 11/1 times 1/1 = 11 because 11 times 1 = 11 so your answer to step to would be 11 cupcakes.
All togheter would be 11 times 14= 154 cupcakes.